Patch Request: Typical Psytrance 'Buzzing' Sound

Hi everyone, for the life of me, I can't find anyone mentioning what this sound is called, let alone how to make it, even though it is in many psytrance tracks. I thought it's just a saw, or uses sync'ing, but I could not get anywhere near it trying these ideas, there is something more to it, something simple and specific, but I don't know what.

It's this buzzing sound (that seems to move down in pitch?) for example here:

or here:

Can anyone help?